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United States Patent |
5,138,003
|
Okumura
,   et al.
|
August 11, 1992
|
Ring opening method and reaction solution
Abstract
Described herein is an oily, transparent reaction product which is prepared
by heat treating at 110.degree.-220.degree. C. a dicyclopentadiene and a
vinyl aromatic compound. This reaction product can be polymerized by
ring-opening in presence or absence of a norbornene monomer to produce a
thermoset polymer. Freezing point of the reaction product is below
10.degree. C.
Inventors:
|
Okumura; Kin-ichi (Kamakura, JP);
Nakano; Munetoshi (Kurashiki, JP);
Tanimoto; Hirotoshi (Kamakura, JP);
Yamato; Motoyuki (Kanagawa, JP)
|
Assignee:
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Nippon Zeon Co., Ltd. (Tokyo, JP)
|
Appl. No.:
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764992 |
Filed:
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September 23, 1991 |
Foreign Application Priority Data
| Jun 04, 1988[JP] | 63-137896 |
Current U.S. Class: |
526/283; 264/328.2; 264/328.6; 264/331.13; 525/245; 525/289; 525/290; 526/75; 526/161; 526/281 |
Intern'l Class: |
C08G 061/02; C08F 279/02 |
Field of Search: |
526/283,75,281,161
525/289,290,245
264/328.2,328.6
585/362
|
References Cited
U.S. Patent Documents
2259496 | Oct., 1941 | Soday | 526/75.
|
2259497 | Oct., 1941 | Soday | 526/75.
|
2371499 | Mar., 1945 | Britton et al. | 526/283.
|
4703098 | Oct., 1987 | Matlack | 526/283.
|
4751337 | Jun., 1988 | Espy et al. | 585/362.
|
4843185 | Jun., 1989 | Ware et al. | 526/75.
|
4853435 | Aug., 1989 | Yamato et al. | 525/193.
|
4899005 | Feb., 1990 | Lane et al. | 585/360.
|
Primary Examiner: Teskin; Fred
Attorney, Agent or Firm: Dunlap; Thoburn T., Kap; George A.
Parent Case Text
This is a continuation of copending application Ser. No. 07/355,579 filed
on May 23, 1989, now abandoned.
Claims
What is claimed is:
1. A process for preparing a polymer comprising polymerizing by
ring-opening in the presence of a metathesis catalyst a reaction product
of a dicyclopentadiene and a vinyl aromatic compound which can undergo the
Diels-Alder reaction with cyclopentadiene, with or without a norbornene
monomer, said norbornene monomer contains at least one norbornene group in
its structure, said reaction product is obtained by heat treating a
dicyclopentadiene and a vinyl aromatic compound in an inert atmosphere at
a temperature range between about 110.degree. to about 220.degree. C. for
a time period of about 0.5 to about 20 hours wherein the molar ratio of
said dicyclopentadiene to said vinyl aromatic compound ranges from about
70/30 to about 30/70.
2. The process of claim 1 wherein said dicyclopentadiene is selected from
dicyclopentadiene itself, substituted dicyclopentadienes, and mixtures
thereof, wherein substituted dicyclopentadienes contain substituents
selected from polar groups, nonpolar groups, and mixtures thereof.
3. The process of claim 1 for preparing a thermoset polymer wherein said
dicyclopentadiene is dicyclopentadiene itself of a purity greater than 90
weight percent; said vinyl aromatic compound is selected from styrene,
alphamethylstyrene, vinyl toluene, isopropenyltoluene, p-t-butylstyrene,
halogenated styrene, vinyl naphthalene, and mixtures thereof.
4. The process of claim 3 wherein said heat treating step is carried out at
150.degree.-200.degree. C. in 1-10 hours.
5. The process of claim 4 wherein weight ratio of said reaction product to
said norbornene monomer is in the range of 100/0-5/95.
6. The process of claim 4 wherein weight ratio of said reaction product to
said norbornene monomer is in the range of 100/0-10/90, said heat treating
step is carried out in an inert atmosphere; and said step of polymerizing
is carried out at a pressure of 0.1 to 100 kg/cm.sup.2.
7. The process of claim 3 including 0.5-20 weight parts of an elastomer,
per 100 weight parts of said thermosetting polymer.
8. The process of claim 4 including 10-10,000 ppm of an antioxidant, based
on the dicyclopentadiene.
9. The process of claim 3 including 1-15 weight parts of an elastomer, per
100 weight parts of said thermosetting polymer, and 100-3,000 ppm of an
antioxidant, based on dicyclopentadiene.
10. The process of claim 3 comprising combining a plurality of streams, one
of which contains said reaction product and a catalyst component of a
metathesis catalyst system, and a second which contains said reaction
product and a cocatalyst component of a metathesis catalyst system, mixing
said one and second streams, and injecting into a mold the mixture of said
one and second streams where said polymerization occurs.
11. The process of claim 10 including the step of polymerizing said mixture
in the mold at a temperature of 40.degree.-200.degree. C.
12. The process of claim 11 wherein weight ratio of said reaction product
to said norbornene monomer is in the range of 100/0-5/95.
13. The process of claim 12 wherein said one and said second streams
include 0.5-20 weight parts of an elastomer, per 100 weight parts of said
thermosetting polymer.
14. The process of claim 13 including 1-15 weight parts of an elastomer,
per 100 weight parts of said thermosetting polymer, and 100-3,000 ppm of
an antioxidant, based on dicyclopentadiene.
15. The process of claim 13 wherein said elastomer is selected from the
group consisting of natural rubber, polybutadiene, styrene-butadiene
copolymer, polyisoprene, styrene-butadiene-styrene block copolymer,
styrene-isoprene-styrene block copolymer, ethylene-propylene-diene
terpolymer, ethylene-vinyl acetate copolymer, ethylvinyl acetate copolymer
and mixtures thereof.
16. The process of claim 1 wherein said norbornene monomer is selected from
the group consisting of substituted or unsubstituted norbornenes,
cyclopentadienes, dicyclopentadienes, dihydrocyclopentadienes,
tricyclopentadienes, tetracyclopentadienes, tetracyclododecenes, and
mixtures thereof.
17. The process of claim 1 wherein said norbornene monomer is selected from
the group consisting of cyclopentadiene, tetracyclododecene, ethyl
tetracyclodecene; ethylidene tetracyclododecene, phenyl
tetracyclododecene; 2-norbornene; 5-methyl-2-norbornene;
5-dodecyl-2-norbornene; 5-ethyl-2-norbornene; 5-butyl-2-norbornene;
5-hexyl-2-norbornene; 5-octyl-2-norbornene; 5-dodecyl-2-norbornene,
norbornene, norbornadiene; ethylidene norbornene, vinyl norbornene, phenyl
norbornene and mixtures thereof.
18. A composition comprising a reaction product and a catalyst component
selected from ring-opening metathesis catalysts, ring-opening metathesis
cocatalysts, and mixtures thereof; said reaction product is obtained by
heating a dicyclopentadiene and a vinyl aromatic compound capable of
undergoing Diels-Adler reaction with cyclopentadiene in an inert
atmosphere and at a temperature range between about 100.degree. to about
220.degree. C. for a time period of about 0.5 to about 20 hours wherein
the molar ratio of said dicyclopentadiene to said vinyl aromatic compound
ranges from about 70/30 to about 30/70.
19. The composition of claim 18 wherein said heating is carried out at
150.degree. to 200.degree. C. for a period of time of 1 to 10 hours,
wherein said reaction product is an oily and transparent liquid at room
temperature.
20. The composition of claim 18 wherein said dicyclopentadiene is
unsubstituted dicyclopentadiene; said vinyl compound is selected from the
group consisting of styrene, alpha-methylstyrene, vinyltoluene,
isopropenyltoluene, p-t-butylstyrene, halogenated styrene,
vinylnaphthalene, and mixtures thereof; said catalysts are selected from
the group consisting of organic ammonium salts of tungsten, molybdenum,
tantalum, and mixtures thereof; said cocatalysts are selected from the
group consisting of alkylaluminum halides, alkoxyalkylaluminum halides,
aryloxyalkylaluminum halides, organic tin compounds, and mixtures thereof;
and said heating is carried out at 150.degree.-200.degree. C. in 1-10
hours.
21. The composition of claim 18 including 0.5-20 weight parts elastomer,
per 100 weight parts of said dicyclopentadiene.
22. The composition of claim 18 wherein said reaction product has viscosity
of less than 100 cps at 30.degree. C., contains less than 5% by weight of
unreacted vinyl aromatic compound, more than 20% by weight aryl norbornene
as a codimer of cyclopentadiene and said vinyl aromatic compound, and more
than 10% by weight of aryl tetracyclododecene, as a cotrimer of
cyclopentadiene and said vinyl aromatic compound.
23. The composition of claim 18 wherein said reaction product has viscosity
of less than 100 cps at 30.degree. C. and contains more than 30% by weight
of aryl norbornene and aryl tetracyclododecene.
24. A ring opened polymer polymerized from the composition of claim 18.
25. Polymer of claim 24 having a glass transition temperature in the range
of from about 140.degree. C. to about 170.degree. C. and having an impact
strength in the range of from about 150 kg/cm to about 250 kg/cm after
heat treatment at 80.degree. C. for 72 hours.
26. The composition of claim 18 further comprising a norbornene monomer.
27. The composition of claim 26 wherein said norbornene monomer is selected
from the group consisting of unsubstituted norbornenes, cyclopentadienes,
dicylopentadienes, dihydrodicyclopentadienes, tricyclopentadienes,
tetracyclopentadienes, tetracyclododecenes, and mixtures thereof.
28. The composition of claim 27 wherein said norbornene monomer is selected
from the group consisting of cyclopentadiene, tetracyclododecene, ethyl
tetracyclodecene; ethylidene tetracyclododecene, phenyl
tetracyclododecene; 2-norbornene; 5-methyl-2-norbornene;
5-dodecyl-2-norbornene; 5-ethyl-2-norbornene; 5-butyl-2-norbornene;
5-hexyl-2-norbornene; 5-octyl-2-norbornene; 5-dodecyl-2-norbornene,
norbornene, norbornadiene; ethylidene norbornene, vinyl norbornene, phenyl
norbornene and mixtures thereof.
29. The composition of claim 18 or 26 further comprising an elastomer.
30. The composition of claim 29 wherein said elastomer is selected from the
group consisting of natural rubber, polybutadiene, styrene-butadiene
copolymer, polyisoprene, styrene-butadiene-styrene block copolymer,
styrene-isoprene-styrene block copolymer, ethylene-propylene-diene
terpolymer, ethylene-vinyl acetate copolymer, ethylvinyl acetate copolymer
and mixtures thereof.
31. A ring-opened polymer polymerized from the composition of claim 26.
32. A ring-opened polymer polymerized from the composition of claim 29.
Description
BACKGROUND OF THE INVENTION
The method for the ring-opening polymerization of a norbornene monomer,
such as dicyclopentadiene (DCPD) or methyl tetracyclododecene (MTD), in a
mold, and the addition of an elastomer as an impact modifier, is well
known.
For example, in Japanese Kokai patent No. Sho 58[1983]-129013, a method for
the manufacture of a thermosetting DCPD homopolymer using a metathesis
catalyst by the reaction injection molding (RIM) method is disclosed.
If an elastomer is added to one or both of the two reaction solutions in
this case, it has been shown that the flexural modulus is decreased
somewhat but the impact strength is increased by 5-10 times.
Furthermore, in Japanese Kokai Patent No. Sho 59[1984]-51911, RIM of cyclic
olefins containing norbornene rings, such as DCPD and MTD, has been
disclosed. Even in this bulk polymerization method, the mixing of an
elastomer as an impact modifier into the monomer reaction solution is
shown.
The ring-opening polymers in these disclosed methods have relatively good
performance in terms of a variety of physical properties required in
engineering plastics, such as impact strength, high modulus of elasticity,
heat resistance, etc. However, in regards to the stringent performance
required to date, it is still difficult to say that they are necessarily
sufficient.
For example, it has been pointed out that the glass transition temperature
(Tg) of the DCPD homopolymers obtained by these methods is insufficient.
As an improvement method, a method has been proposed in which comonomers,
like tetracyclododecadiene,
trimethylolpropane-tris(5-norbornene-2-carboxylate), etc., having two or
more reactive double bonds, are copolymerized so that the number of
crosslinkings is increased by cleavage during the polymerization, see
Japanese Kokai Patent No. Sho 61[1986]-179214. However, in this method,
special comonomers which are difficult to obtain are used.
Furthermore, U.S. Pat. No. 4,703,098, discloses the use of a mixture of
DCPD and its oligomers, obtained by the heat treatment of DCPD. From said
heat-treated product, it is possible to manufacture a thermosetting resin
with an improved glass transition temperature. However, in the storage of
said heat-treated product, a white micropowder is deposited which makes
handling thereof difficult.
For example, if the concentrations of trimers or tetramers of
cyclopentadiene present in the heat-treated product are high, part of the
trimers and tetramers form a white micropowder which is precipitated. This
phenomenon is especially strong when the concentrations of the trimers and
tetramers are more than 15 weight percent or the storage temperature is
less than 10.degree. C. Owing to this settling phenomenon, the piping of
the reaction equipment becomes plugged and variations in the compositions
or physical properties of the thermosetting resins occur. In order to
prevent these problems, the heat-treated product is heated during storage,
the storage tank is stirred, or other troublesome operations are required.
In addition, with an increase in the trimers and tetramers, although the
glass transition temperature will increase, the impact resistance will be
reduced. In particular, there is a drawback in that the impact resistance
is reduced after the heat treatment test.
SUMMARY OF THE INVENTION
The present invention relates to a method for the manufacture of
ring-opened thermosetting resin by the bulk polymerization of a
heat-treated mixture of a norbornene monomer and a vinyl aromatic
compound, and its reaction products. It also relates to a method for the
manufacture of a thermosetting resin having an excellent operability, a
high thermal deformation temperature, and an improved impact strength.
This invention also pertains to a reaction solution containing
heat-treated mixture of DCPD and a vinyl aromatic compound and reaction
products thereof.
DETAILED DESCRIPTION OF THE INVENTION
As a result of the investigations to overcome the problems mentioned above,
the present inventors have discovered that the oily product obtained by
the heat treatment of a mixture of a DCPD and a vinyl aromatic compound
has a high polymerization activity and good processability as a monomer
and that a thermosetting resin can be obtained. Such thermosetting resins,
prepared by polymerizing the oily product alone or with a norbornene
monomer, have high glass transition point, and an improved impact strength
or resistance, especially impact strength after heat treatment test. The
ring-opening polymerization of these materials is carried out in the
presence of a metathesis catalyst system inside a mold of a desired shape.
The gist of the present invention is a method for the manufacture of a
ring-opened thermosetting resin characterized by the fact that an oily
product (A), obtained by the heat treatment of a mixture of a
dicyclopentadiene and a vinyl aromatic compound is allowed to undergo bulk
polymerization in the presence of a metathesis catalyst in a mold. The
oily product can be polymerized in presence of a norbornene monomer.
Furthermore, the present invention provides a method for the manufacture of
a thermosetting resin characterized by the fact that the previously
mentioned oily product (A), or a mixture of product (A) and a norbornene
monomer (B), and an elastomer (C), is allowed to undergo ring-opening bulk
polymerization in the presence of a metathesis catalyst.
Furthermore, the present invention is also directed to reaction solutions
containing the previously mentioned oily product (A), or a mixture of said
product (A) and a norbornene monomer (B), as a monomer component, and a
metathesis catalyst, wherein one formulation would contain the oily
product and a catalyst of the metathesis catalyst system whereas another
formulation would contain an activator or cocatalyst of the metathesis
catalyst system. Other ingredients can be included in either one or both
of the formulations.
The constituent elements of the present invention are described in greater
detail below.
The dicyclopentadienes (DCPDs) are selected from DCPD itself and
substituted DCPDs containing substituents selected from polar and nonpolar
groups. The nonpolar groups, of which there can be one or more on a DCPD,
are selected from hydrogen, alkyl groups of 1-20 carbon atoms, aryl and
alkaryl groups of 6-14 carbon atoms, and saturated and unsaturated
hydrocarbon cyclic groups formed with two ring carbon atoms on a DCPD
containing a total of 4-8 carbon atoms. In a preferred embodiment, the
nonpolar groups are selected from hydrogen, alkyl groups of 1-3 carbon
atoms, and monounsaturated cyclic groups of 5 carbon atoms. The polar
substituents are selected from anhydrides, nitriles, acrylates and
methacrylates, acetates, halogens, carboxyls, carbonyls, and the like.
Dicyclopentadiene itself is preferred.
If DCPDs used as a feedstock in the present invention have a purity
generally greater than 90 percent by weight, preferably greater than 95
percent by weight, it is unnecessary to purify same. Their heat-treated
products have high activities as monomers and render ring-opening polymers
having good physical properties.
The dicyclopentadienes generally contain low boiling point impurities and
high boiling point impurities. Examples of the former mixture, for
example, include C.sub.4-6 hydrocarbon compounds, codimer compounds of
cyclopentadiene (CPD) with butadiene, isoprene, piperylene and other
conjugated diolefins such as vinyl norbornene, isopropenyl norbornene, and
propenyl norbornene. Furthermore, examples of the latter include trimers
of CPD and the codimer compounds of CPD and isoprene such as methyl
bicyclononadiene.
Since the C.sub.4-6 hydrocarbon compounds cause poor molding in the
reaction injection molding, they should be removed. However, in the
present invention, there is a sufficient polymerization activity even if
the purity is less than 98 percent by weight.
The dicyclopentadienes which can be used in the present invention are DCPD
itself, its methyl substituent, ethyl substituent, and other alkyl
substituents containing 1 to 6 carbons in the alkyl group. The feedstock
dicyclopentadienes are endo isomers, exo isomers, or their mixtures. By
heating, dicyclopentadienes are decomposed into cyclopentadiene or its
alkyl substituents.
The vinyl aromatic compounds which are used in the present invention are
those which can undergo the Diels-Alder reaction with cyclopentadiene
(CPD). As specific examples, styrene, .alpha.-methylstyrene, vinyltoluene,
isopropenyltoluene, p-t-butylstyrene, halogenated styrene and other
styrenes, vinylnaphthalene and other vinylnaphthalenes may be mentioned.
Among these, the styrenes are preferred.
The mixing ratios of DCPDs and vinyl aromatics (DCPD/VA) in molar ratios
are 95/5 to 20/80, preferably 80/20 to 25/75, and more preferably 70/30 to
30/70.
If DCPDs are used in a large amount, the oligomers of cyclopentadiene are
generated in a large quantity, no oily product is formed, a waxy product
is obtained, and handling is difficult. In addition, the impact resistance
of the thermosetting resin is damaged. In contrast, if vinyl aromatics are
used in a large amount, the homopolymers of vinyl aromatics are formed in
a large quantity or unreacted vinyl aromatics will remain. As a result,
the physical properties of the thermosetting resins will decrease.
Furthermore during the heat treating, presence of benzene, toluene, xylene,
or other inert solvents in the heat-treating reaction is acceptable. In
this case, it is necessary to have an operation to remove the solvent
after heat treating. Therefore, it is preferable not to use a solvent if
possible.
If necessary, a norbornene monomer (B) may be mixed with the heat-treated
product (A) of a DCPD and a vinyl aromatic compound for use in the present
invention. The norbornene monomers suitable herein contain at least one,
preferably at least two norbornene groups. The norbornene monomers include
substituted or unsubstituted norbornenes, cyclopentadienes,
dicyclopentadienes, dihydrodicyclopentadienes, tricyclopentadienes,
tetracyclopentadienes, tetracyclododecenes, and other norbornene type
monomers which contain at least one norbornene group in their structure.
Specific examples of the norbornene-type monomers suitable herein include
cyclopentadiene, tetracyclododecene, methyl tetracyclododecene, ethyl
tetracyclododecene, ethylidene tetracyclododecene, phenyl
tetracyclododecene, 2-norbornene, 5-methyl-2-norbornene,
5,6-dimethyl-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene,
5-hexyl-2-norbornene, 5-octyl-2-norbornene, 5-dodecyl-2-norbornene,
norbornene, norbornadiene, ethylidene norbornene, vinyl norbornene, and
phenyl norbornene.
Among these, tricyclic compounds represented by DCPDs and tetracyclic
compounds like tetracyclododecene, methyl tetracyclododecene, and the like
are preferred.
As between a DCPD and a norbornene monomer, molar ratio for purposes herein
can vary from 100/0-50/50, preferably 95/5-70/30.
The mixing ratio of the oily product (A) and the norbornene monomer (B) can
be properly selected as desired. Ordinarily, the oily product (A) is 100-5
weight percent, preferably 100-10 weight percent, and the component (B) is
0-95 weight percent, preferably 0-90 weight percent. It is preferable that
in the monomer mixture, aryl tetracyclododecene is present at more than 2
weight percent, preferably more than 3 weight percent, and aryl norbornene
is present at more than 5 weight percent, preferably more than 7 weight
percent.
If the norbornene monomer is a DCPD, the glass transition temperature of
the thermosetting resin will decrease with a decrease in the content of
the oily product (A) in the mixture.
In contrast to DCPD, which solidifies at about 33.degree. C., the mixtures
thereof with heat treatment reaction products are liquid at 10.degree. C.
and the handling or transportation of the liquid is easy. The mixing of
the heat-treated product and the norbornene monomer can be readily carried
out using a power mixer, static mixer, collision mixer, or other mixers.
As conditions for heat treating, a method may be mentioned in which a
mixture of a DCPD and a vinyl aromatic is heated in an inert atmosphere,
such as nitrogen gas, at 110.degree.-220.degree. C., preferably
150.degree.-200.degree. C., for 0.5-20 hours, preferably 1-10 hours.
Heat treating may be either of the batch type or the continuous type. In
order to control the polymerization of vinyl aromatics, the method for the
continuous or intermittent addition of vinyl aromatics and the method for
the midway addition of vinyl aromatics into the continuous process are
available. Furthermore, it is also possible to heat DCPDs to the
temperature mentioned previously for decomposition into CPDs, then to feed
them. In this case, heat treating above 50.degree. C. is acceptable.
The resulting polymer can be heat treated to stabilize physical properties
thereof. This heat treatment can be carried out at an elevated temperature
until a substantially constant impact strength is obtained. This heat
treatment is carried out at an elevated temperature for several hours,
such as at 80.degree. C. for 72 hours.
It is desirable to carry out heat treating in the presence of an
antioxidant. As the antioxidants, those of the phenol system are good. For
example, 4,4'-dioxydiphenyl, hydroquinone monobenzyl ether,
2,4-dimethyl-6-t-butyl phenol, 2,6-d-t-butyl phenol, 2,6-diamyl
hydroquinone, 2,6-di-t-butyl-p-cresol, 4-hydroxymethyl-2,6-di-t-butyl
phenol, 4,4'-methylene-bis-(6-t-butyl-o-cresol), butylated hydroxyl
anisole, phenol condensate, butylated phenol, dialkyl phenol sulfide, high
molecular weight polyvalent phenols, bisphenol, and so on may be
mentioned.
It is also possible to use t-butyl catechol, hydroquinone, resorcinol,
pyrogallol, and other polyvalent phenols.
The amounts of the antioxidants to be used are ordinarily 10-10,000 ppm,
preferably 100-3,000 ppm, based on DCPDs. Furthermore, it is preferable to
use radical polymerization inhibitors in combination therewith.
Examples of radical polymerization inhibitors include p-benzoquinone,
p-quinone dioxime, carbanoxyl, and other quinones, tri-p-nitrophenyl
methyl, diphenyl picryl hydrazyl, and other nitro compounds, nitroso
benzene and other nitroso compounds, p-phenyl diamine and other amino
compounds, dimethyl dithiocarbamic acid salts, phenothiazine, and other
organic sulfur compounds, and iodine, sulfur, sodium nitrite, and other
inorganic compounds may be mentioned. The amount of the radical
polymerization inhibitors is 100-3,000 ppm.
The heat-treated products obtained can be used as such as feedstocks for
the manufacture of thermosetting resins by ring-opening polymerization.
However, it is preferable to remove cyclopentadienes (CPDs), unreacted
vinyl aromatics, and other low boiling point substances formed by the
decomposition of DCPDs.
The products obtained by the heat treating of DCPDs and vinyl aromatics are
generally colorless, transparent, oily substances. Their viscosities are
less than 200 centipoise at 30.degree. C., preferably less than 100
centipoise, and more preferably less than 50 centipoise.
Said products contain the unreacted DCPDs, a small amount of unreacted
vinyl aromatics, the oligomers of cyclopentadienes (CPDs), codimers of
CPDs and vinyl aromatics such as phenyl norbornene, naphthyl norbornene,
the Diels-Alder reaction products of CPDs and the previously described
codimers such as phenyl tetracyclododecene or naphthyl tetracyclododecene,
polymers of vinyl aromatics, and the like.
As the heat-treated products in the present invention, those containing
less than 5 weight percent of the unreacted vinyl aromatics, especially
less than 2 weight percent, are preferred. If vinyl aromatics are in a
large quantity, the glass transition temperature of thermosetting resins
will not be sufficiently high.
The content of aryl norbornene as a codimer of CPD and a vinyl aromatic is
generally more than 10 weight percent, preferably more than 20 weight
percent. Furthermore, the content of aryl tetracyclododecene as a cotrimer
of a CPD and a vinyl aromatic is generally more than 3 weight percent,
preferably more than 10 weight percent.
The sum of the reaction products of CPDs and vinyl aromatics such as aryl
norbornene or aryl tetracyclododecene in the reaction product is more than
15 weight percent, preferably more than 30 weight percent. If said
reaction products are increased, the glass transition temperature of the
thermosetting resin is increased and the impact strength is also improved.
Therefore, higher contents are more preferable.
The contents of the oligomers with the trimers and tetramers of CPDs as the
major components are generally less than 40 weight percent, preferably
less than 25 weight percent. If the contents of said oligomers are high,
the heat-treated products will be white turbid or waxy and handling will
be difficult. Furthermore, with an increase in said oligomers, the glass
transition temperature of the thermosetting resins is increased. On the
other hand, the impact resistance, especially the impact resistance after
the heat-resistance deterioration test, will decrease undesirably.
The sum of aryl norbornene and aryl tetracyclododecene is preferably more
than the same amount of the CPD oligomers, especially more than twice, for
the physical properties of thermosetting resins.
The contents of the polymers of vinyl aromatics, like polystyrene, are less
than 30 weight percent, preferably 0.1-15 weight percent. Within this
range, the polymerization activity will not be damaged. Furthermore, the
physical properties of the thermosetting resins formed are essentially
unaffected. However, if the content is too high, the viscosity of the
heat-treated product will be too high and difficulty in operability will
occur. Furthermore, the glass transition temperature is also decreased.
In the present invention, an elastomer may also be present mainly from the
viewpoint of improving the impact strength. The elastomers which can be
used include natural rubber, polybutadiene, styrene-butadiene copolymer
(SBR), polyisoprene, styrene-butadiene-styrene block copolymer (SBS),
styrene-isoprene-styrene block copolymer (SIS), ethylene-propylene-diene
terpolymer (EPDM), ethylene-vinyl acetate copolymer (EVA), and their
hydrides. The elastomers may be used alone or as a mixture of two or more.
The elastomer is generally used by pre-dissolving it in a reaction solution
containing the previously mentioned product (A) or a mixture of said
product (A) and norbornene monomer (B).
If a reaction solution containing a monomer has a low viscosity, the
viscosity of such a reaction solution can be properly adjusted by
dissolving the elastomer therein.
The amounts of these elastomers are ordinarily 0.5-20 parts by weight,
preferably 1-15 parts by weight, with respect to 100 parts by weight of
the thermosetting resins. If the amount of the elastomer is too low, the
effect of rendering the impact resistance will be small. On the other
hand, if it is too high, the viscosity of the reaction solution will be
too high and the molding operability will be poor. Furthermore, the
thermal deformation temperature or the flexural modulus of the
thermosetting resin composition will decrease if too much elastomer is
used.
As the catalyst components of the metathesis catalyst system for use in the
present invention, any of the metathesis catalyst systems known as the
catalysts for the bulk polymerization of norbornene monomers are
acceptable. This includes those disclosed by Japanese Kokai Patents Nos.
Sho 58[1983]-127728, Sho 58[1983]-129013, Sho 59[1984]-51911, Sho
60[1985]-79035, Sho 60[1985]-186511, and Sho 61[1986]-126115, U.S. Pat.
Nos. 4,380,617, 4,400,340, and 4,481,344,European Unexamined Patents
142,861 and 181,642. These are no special instructions.
As suitable catalysts, halides, oxyhalides, oxides, organic ammonium salts,
and so on of tungsten, molybdenum, tantalum, and the like may be
mentioned. Specific examples include tungsten hexachloride, tungsten
oxytetrachloride, tungsten oxide, tridodecylammonium tungstate,
methyltricaprylammonium tungstate, tri(tridecyl)ammonium tungstate,
trioctylammonium tungstate, and other tungsten compounds; molybdenum
pentachloride, molybdenum oxytrichloride, tridodecylammonium molybdate,
methyltricapryl trioctylammonium molybdate, and other molybdenum
compounds; and tantalum pentachloride and other tantalum compounds. Among
these, it is preferable to use the catalysts which are soluble in the oily
product or the norbornene monomer. From this viewpoint, organic ammonium
salts are preferred. If the catalyst is a halide, it can be solubilized by
pretreatment with an alcohol compound or a phenol compound. Furthermore,
if necessary, benzonitrile, tetrahydrofuran, and other Lewis bases, acetyl
acetone, acetoacetic acid alkyl esters, and other chelating agents may be
used in combination. By doing so, pre-polymerization can be prevented.
The activators or cocatalysts of the metathesis catalyst system include
alkylaluminum halides, alkoxyalkylaluminum halides, aryloxyalkylaluminum
halides, and organic tin compounds. Specific examples of suitable
cocatalysts also include ethylaluminum dichloride, diethylaluminum
monochloride, ethylaluminum sesquichloride, diethylaluminum iodide,
ethylaluminum diiodide, propylaluminum dichloride, propylaluminum
diiodide, isobutylaluminum dichloride, ethylaluminum dibromide,
methylaluminum sesquichloride, methylaluminum sesquibromide,
tetrabutyltin, and reaction products of alkylaluminum halides with an
alcohol.
Among these activators, an alkoxyalkylaluminum halide or
aryloxyalkylaluminum halide can be adjusted to have a proper pot life at
room temperature. Specific examples include those in Japanese Kokai Patent
No. Sho 59[1984]--51911 and U.S. Pat. No. 4,426,502. In the case of an
alkylaluminum halide, polymerization can be initiated immediately when a
catalyst is mixed with it. In such a case, the initiation of
polymerization can be delayed using an activator modified with an ether,
ester, ketone, nitrile, or an alcohol, see, for example, Japanese Kokai
Patents Nos. Sho 58[1983]-129013, Sho 61[1986]-210814, and U.S. Pat. No.
4,400,340. If these modifiers are not used, it will be necessary to take
into account aspects of the apparatus and operation so that those with a
short pot life can also be used. Furthermore, it is also acceptable to
use, in addition to the catalyst and the activator, a halogen source such
as chloroform, carbon tetrachloride, hexachlorocyclopentadiene, other
halogenated hydrocarbons, silicon tetrachloride, magnesium tetrachloride,
lead tetrachloride, and other metal halides, as disclosed by, for example,
Japanese Kokai Patent No. Sho 60[1985]-79035 and U.S. Pat. No. 4,481,344.
The catalyst component can ordinarily be used at a ratio 0.05-1 part by
weight, preferably 0.1-0.7 part by weight, based on 100 parts by weight of
the total monomer, i.e., the total amount of oily product (A) and the
norbornene monomer (B) if the norbornene monomer is used.
The activators or cocatalysts are ordinarily used at a molar ratio of
0.1-200, preferably 2-10 with respect to the catalyst components.
It is preferable to use both the metathesis catalyst and the activator by
dissolving them in monomers. However, they may also be used in suspension
or dissolved in a small amount of a solvent.
In the present invention, the thermosetting resin is prepared by a
polymerization method in which a monomer and metathesis catalyst system
are introduced into a mold of a desired shape and bulk polymerization is
carried out in the mold. It does not matter if a small amount of an inert
solvent is present.
Ordinarily, the monomer is divided into two liquids placed in separate
vessels. A metathesis catalyst is added into one of them, and an activator
is added into the other so that two stable reaction solutions are
prepared. If an elastomer is used, it is dissolved in either or both of
these reaction solutions.
These two reaction solutions are mixed then poured into a forming mold
maintained at an elevated temperature. The ring-opening polymerization is
initiated here to yield a thermosetting resin.
The impingement mixing apparatus known conventionally as a RIM molding
apparatus in the present invention can be used for mixing of the two
reaction solutions. In this case, the vessels containing the two reaction
solutions are used as supply sources of separate streams. The two streams
are instantaneously mixed within a mixing head of a RIM machine. Next, it
is poured into a high temperature mold where bulk polymerization is
immediately carried out to yield a thermosetting resin.
Although the impingement mixing apparatus can be used in this manner, the
present invention is not restricted to such a mixing means. If the pot
life at room temperature is more than 1 hour after completion of the
mixing of the two reaction solutions in the mixer, it may be injected or
poured into a preheated mold, as described, for example, in Japanese Kokai
Patent No. Sho 59[1984]-51911 and U.S. Pat. No. 4,426,502, or it can be
poured continuously. In this type of apparatus, the mixture can be
injected into a mold as with the impingement mixer. Furthermore, such RIM
apparatus has an advantage of operating at a low pressure.
In addition, the present invention is not restricted to a method using two
reaction solutions. As is easily understandable by those in the industry,
a variety of modifications is possible, for example, a monomer and a
desired additive may be placed in the third vessel for use as a third
stream.
The mold temperature is ordinarily more than 30.degree. C., preferably
40.degree.-200.degree. C., more preferably 50.degree.-120.degree. C. The
mold pressure is generally 0.1 to 100 kg/cm.sup.2.
The polymerization time can be properly selected. Ordinarily, it is shorter
than about 20 minutes and preferably shorter than 5 minutes. However, it
may be longer than this.
The reaction solutions are generally stored or handled under an inert gas
atmosphere, such as nitrogen gas. However, if a solution is insensitive to
atmosphere, it need not be stored or handled in an inert atmosphere. The
mold need not necessarily be sealed with an inert gas.
By blending fillers, foaming agents, flame retardants, antioxidants,
pigments, coloring agents, high molecular weight reforming agents, and a
variety of other additives, or using glass fibers, carbon fibers, aramide
fibers, glass mats, and other reinforcing materials, the characteristics
of the thermosetting resins of the present invention can be reformed.
The additives may be blended with one or both of the reaction solutions or
placed in the cavity of the mold.
Examples of fillers or reinforcement agents include milled glass, carbon
black, talc, calcium carbonate, mica, and other inorganic fillers.
In addition to elastomers used as the high molecular weight agents, there
are hydrogenation additives for the thermally polymerized DCPD resins.
They are dissolved in the reaction solutions.
The bulk polymers obtained by the method of the present invention are
thermosetting resins which become hard solids upon cooling. The glass
transition temperature (Tg) depends on the monomer composition. However,
Tg is higher than Tg for the homopolymers of dicyclopentadienes. It is
generally higher than 120.degree. C., preferably higher than 140.degree.
C.
Furthermore, in comparison with the conventional method using
cyclopentadiene oligomers as comonomers, the copolymers herein have a much
higher impact strength. In particular, the improvement in the impact
strength after thermal treatment is remarkable.
The following examples are presented so that the present invention can be
more specifically explained. However, the present invention is not to be
restricted to these examples. Parts, ratios and percentages are all on a
weight basis.
EXAMPLE 1
50 parts of 98.5% purity DCPD containing 500 ppm of 2,6-di-tert-butyl
phenol (BHT) and 100 ppm of t-butyl catechol with 50 parts of 99.90%
purity styrene where charged into an autoclave. The molar ratio of DCPD to
styrene was 44:56. After sufficient nitrogen sparging, the mixture was
heated to 170.degree. C. and reacted for 4 hours. Afterwards, it was
cooled to 80.degree. C. and evacuated to 5 Torr. 1.9 parts of a low
boiling point substance were removed by evaporation from the autoclave. It
was then cooled to room temperature to yield 98.1 parts of a colorless,
transparent, oily substance. This oily substance had a viscosity of about
20 centipoise at 30.degree. C. and the freezing point was under
-10.degree. C.
The composition of the oily product was as follows:
Unreacted DCPD: 14%
Unreacted styrene: 1%
Trimer and Tetramer of CPD: 10%
Phenyl norbornene: 43%
Phenyltetracyclodecene: 21%
Polystyrene: 10%
Other high-boiling-point substances: 1%
This oily product was placed in two vessels. To one vessel were added 0.4
part diethylaluminum chloride (DEAC), 0.15 part n-propanol, 0.36 part
silicon tetrachloride, and 5 parts styrene-isoprene-styrene block
copolymer Kraton 1170, manufactured by the Shell Co. This was Solution A.
To the other vessel, 0.3 part tri(tridecyl)ammonium molybdate was added per
100 parts of the oily product. This was Solution B.
Solution A and Solution B were pumped with gear pumps to a mixer so that
they were in a volumetric ratio of 1:1. Next, it was rapidly poured into a
mold having a volume of 200 mm.times.200 mm.times.3 mm and heated to
70.degree. C. The pouring time was about 10 seconds. Reaction was carried
out in the mold for 3 minutes. A series of these operations was carried
out in a nitrogen gas atmosphere.
The glass transition temperature (Tg) measured with a differential scanning
calorimeter of a product obtained in this manner was measured to be
158.degree. C. The DuPont impact value (exhibiting the fracture strength
during the falling of a hammer having a front tip shape with a radius of
7.9 mm according to the falling hammer impact strength of JIS K 7211) was
600 kg/cm.
The DuPont impact strength after heat treatment of the polymer at
80.degree. C. for 72 hours was 250 kg/cm.
EXAMPLE 2
Using the heat-treated product of Example 1, mixtures with DCPD at the
compositions shown in Table I were prepared. In the same manner as in
Example 1, Solution A and Solution B were prepared. By forming, molded
products were obtained. The various physical properties of these molded
products are shown in Table I.
In regard to the freezing points of the mixtures, none of the mixtures of
the present invention froze even at -10.degree. C., compared with the fact
that DCPD froze at 33.degree. C.
TABLE I
______________________________________
Present Comparative
Invention Examples
______________________________________
Test Nos. 2-1 2-2 2-3 2-4
DCPD/Product 30/ 50/ 70/ 100/
Mixing Ratio 70 50 30 0
Glass Transition
156 154 153 150
Temperature (Tg)
Du Pont Impact
600 500 400 250
Value (kg/cm)
Du Pont Impact
250 170 150 100
Value after 80.degree. C.
@72 hours. (kg/cm)
______________________________________
EXAMPLE 3
Oily products were obtained by the same operation as in Example 1 except
that the amounts of the DCPD and styrene feedstocks charged were those
shown in Table II. The compositions of the oily products obtained, the
presence or absence of the white turbidity state in the solutions, and the
freezing points are shown in Table II.
Molded products were obtained in the same manner as in Example 1 except
that these oily products were used. The various physical properties of the
molded products obtained are shown in Table II.
TABLE II
______________________________________
Examples of
Comparative
the Present
Examples Invention
Test Nos. 1 2 3
______________________________________
Amounts of feedstocks charged
100 65 34
(molar ratios)
Styrene 0 35 66
Compositions of reaction products
Unreacted DCPD 40 27 8
Unreacted styrene -- 0.4 2
Trimer and tetramer of CPD
60 18 3
Phenyl norbornene -- 29 49
Phenyl tetracyclododecene
-- 17 24
Polystyrene -- 8 14
Others -- 0.6 24
States of the reaction products
White turbidity state
Waxy, white
Color- Color-
precipitate
less, less,
in a large trans- trans-
quantity parent parent
Freezing point (.degree.C.)
50 -10> -10>
RIM molded products
Glass transition temperature.
190 168 150
(.degree.C.)
DuPont impact value (kg/cm)
150 600 >700
DuPont impact value after 80.degree. C.
40 220 250
@72 hours (kg/cm)
______________________________________
EXAMPLE 4
Using 50 parts of 98.5% purity DCPD containing 100 ppm of t-butyl catechol
and 1,000 ppm of 4,4'-methylene-bis-(6-t-butyl-o-cresol) with 50 parts of
98.0% purity vinyltoluene, the same heat treatment as in Example 1 was
carried out. A colorless, transparent, oily product with a viscosity of 10
cps at 30.degree. C. was obtained.
The composition of this oily product was as follows:
Unreacted DCPD: 8%
Unreacted vinyltoluene: 2%
Trimer and Tetramer of CPD: 15%
Tolyl norbornene: 51%
Tolyl tetracyclododecene: 17%
Polyvinyltoluene and other higher boiling point substances: 7%
A molded product was obtained by the same method as in Example 1 except
that a mixture of 30 parts of this oily product and 70 parts of DCPD was
used.
The freezing point of the mixture was under -10.degree. C. The glass
transition temperature (Tg) of the molded product obtained was 155.degree.
C. The DuPont impact value was 600 kg/cm and was 250 kg/cm after thermal
treatment.
EXAMPLE 5
In this example, a continuous feeding technique is demonstrated.
A reaction solution obtained by mixing equal weights of 98.5% purity DCPD
containing, 1,000 ppm of 4,4'-methylenebis(2,6-di-t-butyl phenol) and
99.9% purity styrene was supplied at a feeding rate of 1.0 liter per hour
through a feedstock supply tube into a 3 liter reactor equipped with a
heating and cooling device outside and maintained at a constant
temperature of 160.degree. C.
The solution leaving said reactor was introduced through another product
solution outlet tube into a separate 3-liter reactor. Afterwards, it was
passed through a product solution outlet tube and a constant-pressure
valve into a flash distillation column operating at a vacuum of 5 Torr.
Here, at a rate of 0.05 liter/hr, the low boiling point substance was
vaporized, liquefied by a condensation heat exchanger, and removed from
the system.
The heat-treated product was supplied to the desired application through an
outlet tube. The heat-treated product obtained was colorless and
transparent. Its composition was as follows:
Unreacted DCPD: 12%
Unreacted styrene: 2%
Trimer and tetramer of CPD: 8%
Phenyl norbornene: 51%
Phenyl tetracyclododecene: 17%
Polystyrene: 9%
Others: 1%
A molded product was obtained in the same manner as in Example 1 except
that a mixture consisting of 30 parts of this oily product and 70 parts of
DCPD was used.
The freezing point of the mixture was under -10.degree. C. The glass
transition temperature of the molded product obtained was 155.degree. C.
The DuPont impact value was 500 kg/cm and the DuPont impact value after
the thermal treatment was 200 kg/cm.
EXAMPLE 6
As in Example 5, in addition to the supply from the feedstock supply tube,
a feedstock solution consisting of 30 parts of DCPD and 70 parts of
styrene was supplied additionally at a rate of 0.3 liter/hr through
another feedstock supply tube into a reactor. The molar ratio of DCPD to
styrene in the total supplied feedstocks was 40:60. The oily product
obtained was colorless and transparent. Its composition was as follows:
Unreacted DCPD: 15%
Unreacted styrene: 2%
Trimer and tetramer of CPD: 5%
Phenyl norbornene: 53%
Phenyl tetracyclododecene: 21%
Polystyrene: 3%
A molded product was obtained by the same method as in Example 1 except
that a mixture consisting of 30 parts of this oily product and 70 parts of
DCPD was used.
The freezing point of the mixture was under -10.degree. C. The glass
transition temperature of the molded product was 165.degree. C. The DuPont
impact value was 500 kg/cm and the DuPont impact value after the thermal
treatment was 190 kg/cm.
EXAMPLE 7
A reaction was carried out according to Example 5 except that DCPD was
supplied additionally through a feedstock supply tube at a rate of 0.3
liter/hour, heated to 180.degree. C. in a heat exchanger with an internal
volume of 0.2 liter, and supplied into a reactor, as in Example 5. The
molar ratio of the DCPD to styrene in the total supplied feedstocks was
56:44.
The oily product obtained was colorless and transparent. Its composition
was as follows:
Unreacted DCPD: 18%
Unreacted styrene: 1%
Trimer and tetramer of CPD: 8%
Phenyl norbornene: 45%
Phenyl tetracyclododecene: 23%
Polystyrene: 3%
Others: 2%
A molded product was obtained by the same method as in Example 1 using a
mixture consisting of 20 parts of this oily product and 80 parts of DCPD.
The freezing point of the mixture was under -10.degree. C. The glass
transition temperature of the molded product obtained was 170.degree. C.
The DuPont impact value was 600 kg/cm and the DuPont impact value after
the thermal treatment was 220 kg/cm.
According to the present invention, using an oily, easy to handle monomer
obtained from a DCPD and a vinyl aromatic compound as feedstocks, a
thermosetting resin can be obtained with a better thermal deformation
temperature (glass transition temperature) and falling-hammer impact
strength, especially the falling-hammer impact strength after thermal
treatment, than with the conventional DCPD polymers. The thermosetting
resin of this invention has an excellent effectiveness which makes it
possible for use in a variety of fields where heat resistance and impact
strength are required.
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